Hypervalent iodine compounds are generated by oxidation of organic iodides and feature 3-centered, 4-electron (3c-4e) bonding at iodine. Hypervalent iodine reagents are broadly useful chemical oxidants in organic synthesis, with demonstrated applications in diverse reactions such as substrate hydroxylation and amination chemistry, olefin functionalization, and oxidative dearomatization. The broad utility of these reagents derives from facile ligand exchange chemistry at iodine, which allows use of hypervalent iodine reagents to accomplish a diverse set of group-transfer and substrate-oxidation reactions. Liabilities of hypervalent iodine reagents include 1) the need to stoichiometric quantities and 2) the common use of wasteful metal-based oxidants, such as KMnO4, NaIO4, and oxone, or organic peracids, such as mCPBA, in the synthesis of these chemicals. A need exists for a cost effective, efficient method of synthesis of these useful reagents for organic synthesis.
Dioxygen (O2) is an attractive oxidant for synthetic chemistry because it displays a large reduction potential, is readily available, and is environmentally benign. Selective and efficient utilization of O2 in synthesis, however, is challenging because the triplet ground state of O2 gives rise to poorly selective radical chemistry. In addition, one must manage the disparate electron inventories of 4-electron reduction of O2 with the 2-electron oxidations common in synthesis. Development of new chemical strategies to couple O2 reduction directly to substrate oxidation would underpin development of more sustainable synthetic methods.
The present invention fulfills these unmet needs by providing a method of aerobic oxidation of aryl iodides to aryl hypervalent iodine reagents and by providing a broad access to new oxidation methods of organic substrates directly utilizing dioxygen.